Figure 2.

The amino acid sequences encoded by the mouse ep (MEP-1, accession no. U97149, top row) and human HPS (10, accession no. U65676, bottom row) genes. Vertical bars between the sequences indicate identity. Similarity is indicated by dots between the sequences, with two dots indicating a higher degree of amino acid similarity and less evolutionary distance than one dot. Dashes indicate nonconservation or gaps. Key features of the mouse sequence are indicated as follows: single underline, helix–loop–helix motif; overline, polyglutamic acid motif; double underline, transmembrane domain; asterisk, point of IAP element insertion; and bold, lysosome/endosome trafficking motif [(D or E)-X-X-X-X-L-L; ref. 41]. Amino acid homologies depicted represent analysis by the gap program of the GCG sequence analysis software (Wisconsin Package). Protein subsequence analysis and hydropathy plots were performed with the MacVector sequence analysis program (International Biotechnologies). Transmembrane domain assignments were determined with a window size of 20 and the Goldman, Engelman, and Steitz hydrophilicity scales (40).